Activation time for target based high speed serving cell change

ABSTRACT

A method for setting up an activation time of a cell change of user equipment includes receiving a timing offset from a network controller through an active set update procedure and calculating a high speed downlink shared channel cell change activation time based on the timing offset. The activation time indicates when the user equipment can move to the target cell. The method also includes transmitting the calculated activation time to the network controller and receiving an approval of the downlink shared channel high speed cell change from the network controller. Additionally, the method includes moving from the serving cell to the target cell at the activation time if the approval has been received.

This application claims the benefit of U.S. Provisional Application No.61/041,283, filed Apr. 1, 2008, the disclosure of which is fullyincorporated herein by reference.

TECHNICAL FIELD

The present solution relates to a method and arrangement in atelecommunications system, in particular it relates to a method andarrangement for synchronizing a high speed downlink shared channel(HS-DSCH) serving cell change (HSCC) procedure in a telecommunicationssystem.

BACKGROUND

A Universal Mobile Telecommunications System (UMTS) or third generation(3G) network can be separated into a number of major components, namelyone or more core networks which are responsible for setting up andcontrolling user sessions, and a UMTS radio access network (UTRAN) whichcontrols access to the air interface. The interface between UTRAN anduser equipment (UE) is provided by nodes that may be referred to as“Node B” (analogous to base stations in 2G/GSM networks) or basestations. NodeBs are responsible for transmitting and receiving dataover the air interface and are controlled by radio network controllers.User and control data are routed between a base station and a corenetwork via the base station and the radio network controllers. Theinterface between a base station and a radio network controller isreferred to as the lub interface. The interface between two radionetwork controllers in the same network is referred to as the lurinterface. A lu interface carries user traffic (such as voice or data)as well as control information, and is mainly needed for soft handovers.Soft handover refers to a feature used by the Code Division MultipleAccess (CDMA) and Wideband Code Division Multiple Access (WCDMA)standards, where a user equipment, such as a cell phone, issimultaneously connected to two or more cells (or cell sectors) during acall. On the uplink (user equipment-to-cell-site), all the cell sitesectors that are actively supporting a call in soft handover send thebit stream that they receive back to the radio network controller, alongwith information about the quality of the received bits. The radionetwork controller examines the quality of all these bit streams anddynamically chooses the bit stream with the highest quality. Again, ifthe signal degrades rapidly, the chance is still good that a strongsignal will be available at one of the other cell sectors that aresupporting the call in soft handover.

In UTRAN, the high-speed downlink shared channel (HS-DSCH) does not usesoft handover as dedicated channels do. Instead, a procedure calledHS-DSCH serving cell change (HSCC) is utilized to make a hard handover.Soft handover is still used for the uplink, and an active set is managedin the same way as for non-high speed user equipment. The active setcomprises a list of all active cells the user equipment is connected toin uplink soft handover. The user equipment continuously measures acommon pilot channel (CPICH) and comprises a hysteresis to be fulfilledduring a certain time (time to trigger). The update procedure for thelist of active set of cells is schematically illustrated in FIG. 1. Theactive set update procedure is triggered by measurement report 1 a, 1 bor 1 c, 101 informing the network controller, e.g. a serving radionetwork controller SRNC, that new cells have fulfilled the criterions tobe added (measurement report 1 a), deleted (measurement report 1 b) orreplaced (measurement report 1 c) in the active set. The measurementreport 1 a, 1 b, 1 c is sent from the user equipment to a networkcontroller, e.g. a serving radio network controller SRNC. A servingradio network controller is a type of radio network controller serving aparticular user equipment and manages the connections towards that userequipment. When in HS-DSCH operation, the downlink is not in softhandover. Instead, one of the cells (typically the strongest) in theactive set is marked as current HS-DSCH serving cell. The networkcontroller then performs a radio link addition 102, and sets up therequired radio links by sending and receiving setup request and response103, 104 to/from the base station. The network controller transmits anactive set update message 105 to the user equipment. When the userequipment has received the active set update from the networkcontroller, it prepares 106 a processing, i.e. it reads the message andapplies the new configuration, e.g. adds or deletes a radio link. Theuser equipment sends an active set update complete message 107 to thenetwork controller confirming that the active set update was complete.The duration of an active set update procedure may, as an example, becalculated as follows:T _(asu) =Ttrig1a+2*T _(Uu)+2*T _(lub)where

-   -   Ttrig1a=Time to trigger measurement report 1 a=320 ms    -   T_(Uu)=Uu (Radio Interface) delay=100 ms    -   T_(lub)=lub (Radio Network Controller-NodeB Interface) delay=10        ms    -   T_(asu)=Time for active set update

The signalling sequence for a (regular) HSCC procedure for hard handoveris schematically shown in a combined flow and signalling diagram in FIG.2. The user equipment performs a handover evaluation 200 to determinewhether a handover shall be performed. This is triggered by a neighbourcell, target cell, being stronger than of the current cell, servingcell. A measurement report 1 d is sent 201 from the user equipment tothe network controller, e.g. the serving radio network controller(SRNC), indicating that another cell in the list of active set of cellshas become the strongest one. As an example, the measurement report 1 dis triggered to be sent from the user equipment when the measured commonpilot channel level (CPICH) of the target cell is stronger than theserving cell by a certain hysteresis for a given time, governed by aparameter Ttrig1d (time to trigger measurement report 1 d).

When not considering possible processing delays in the networkcontroller and the user equipment, i.e. in simulation, the delay of thecell change procedure, T_(cc), used may, as an example, be calculated asfollows:T _(cc) Ttrig1d+T _(Uu)+2*T _(lub) +T _(ActivationTime)where

-   -   T_(cc)=Delay of cell change procedure    -   Ttrig1d=time to trigger measurement report 1 d    -   T_(Uu)=Uu (Radio Interface) delay=100 ms    -   T_(lub)=lub (Radio Network Controller-NodeB Interface) delay=10        ms    -   T_(ActivationTime)=Activation time

When the network controller receives the measurement report 1 dindicating the existence of this stronger cell, the network can take thedecision to change the serving cell, i.e. it takes a handover decision202. When a cell change is triggered, the network controller configuresthe source and target base stations (shown as only one base station inFIG. 2) with the new configuration, and the network controller alsoconfigures the lub transport bearer. The network controller sends aradio link reconfiguration prepare message 203 to the base stations, andreceives in return a radio link reconfiguration ready message 204 whenthe reconfiguration is ready. When both base stations (serving andtarget) have acknowledged the configuration, the network controllercalculates the activation time 205 for the new configuration in case theswitch to the new configuration is a synchronized procedure, meaningthat the user equipment and the network controller shall move to the newconfiguration at the same time. The calculated activation time isrelative to a connection frame number (CFN). An offset is needed tocover for the time it takes to transmit the reconfiguration commitmessages 206 to both the user equipment and the base stations. Thenetwork controller sends a physical channel reconfiguration message 207to the user equipment. The user equipment prepares a processing 208,i.e. it reads the message from the network controller and executes thehandover 209, i.e. applies the new configuration, e.g. adds or deletes aradio link for the handover. When the handover is complete, the userequipment may send a physical channel reconfiguration complete message210 to the network controller.

There is however a problem for user equipments travelling at very highspeed, since the link quality of the serving cell, i.e. source cell, maydegrade before the cell change procedure to the target cell iscompleted. If this happens before the network controller is able tosuccessfully transmit the physical channel reconfiguration message 207,the network controller will no longer be able to reach the userequipment and the call will be dropped.

Enhancements to the HS-DSCH serving cell change procedure areconsequently required regarding radio protocol procedures andstructures, lub/lur protocols and user equipment, base station and radioresource management (RRM) performance requirements.

SUMMARY

It is thus an object of the present solution to provide an improvedprocedure for synchronizing a High-Speed Downlink Shared Channel(HS-DSCH) Serving Cell Change (HSCC) procedure in a communicationssystem.

Further objects and advantages are evident from the following.

The objectives set forth above are achieved by providing, in a firstaspect of the present solution, a method in a user equipment for settingup an activation time of a cell change of the user equipment from aserving cell to a target cell in a wireless communications network.After receiving a timing offset from a network controller, the userequipment calculates a cell change activation time based on the timingoffset. The user equipment then transmits the calculated activation tothe time controller. Then the user equipment receives an approval of thecell change from the network controller. The user equipment will thenmove from the serving cell to the target cell at the activation time ifit has received the approval.

In a second aspect of the solution there is provided a method in anetwork controller for setting up an activation time of a cell change ofa user equipment from a serving cell to a target cell in a wirelesscommunications network. The network controller transmits a timing offsetto the user equipment and receives an activation time from the userequipment. Then the network controller decides to move the userequipment to the target cell. The serving cell and the target cell areconfigured with the activation time. The network controller receives aconfiguration confirmation from the serving cell and the target cell,and the network controller sends an approval of the cell change to theuser equipment.

In a third aspect of the present solution there is provided anarrangement in a user equipment in a wireless communication network. Theuser equipment is arranged to be capable of setting up an activationtime of a cell change from a serving cell to a target cell. The userequipment arrangement comprises a receiver arranged to receive a timingoffset from a network controller through an interface, a processorarranged to calculate a cell change activation time based on the timingoffset. The arrangement further comprises a transmitter arranged totransmit the activation time through the interface to the networkcontroller. The receiver is further arranged to receive an approval ofthe cell change through the interface. The processor is further arrangedto move from the serving cell to the target cell at the activation timeif the approval has been received.

In a fourth aspect of the present solution there is provided anarrangement in a network controller. The network controller is arrangedto set up an activation time of a cell change of a user equipment from aserving cell to a target cell in a wireless communications network. Thenetwork controller arrangement comprises a transmitter arranged totransmit a timing offset to the user equipment, a receiver arranged toreceive an activation time from the user equipment. The arrangementfurther comprises a processor arranged to decide to move the userequipment to the target cell, and arranged to configure the serving celland the target cell with the activation time. The receiver is furtherarranged to receive a configuration confirmation from the serving celland the target cell, and the transmitter is further arranged to send anapproval of the cell change to the user equipment.

Since the user equipment can decide an activation time in which it willmove from a source cell to a target cell it allows a synchronizedoperation for HS-DSCH serving cell change (HSCC). The synchronizedoperation may also be possible when the cell change command is signalledover HS-SCCH from the target base station. This provides an advantage ofsimplifying L1 (lower physical layer) termination and user planehandling over the interface between a base station and a networkcontroller (lub). A further advantage is that the offset used tocalculate the activation time is controlled by the network controller,and can thus be optimised based on the network configuration and delays.Another advantage of this is that it allows the network controller anduser equipment to simultaneously change from source to target cellduring handover.

Further advantages of the present solution and embodiments thereof willappear from the following detailed description of the solution.

It goes without saying that the above aspects of the solution may becombined in the same embodiment. The objects of this solution areobtained as described in the accompanying claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The solution will now be further described in more detail in thefollowing detailed description by reference to the appended drawingsillustrating embodiments of the solution and in which:

FIG. 1 is a combined flowchart and signalling diagram illustrating aprior art active set update procedure.

FIG. 2 is a combined flowchart and signalling diagram illustrating aprior art procedure for HS-DSCH serving cell change.

FIG. 3 is a schematic block diagram illustrating a wirelesscommunication network.

FIG. 4 is a combined flowchart and signalling diagram illustrating asynchronized cell change procedure.

FIG. 5 is a flowchart illustrating embodiments of a method in a userequipment.

FIG. 6 is a flowchart illustrating embodiments of a method in a networkcontroller.

FIG. 7 is a schematic block diagram illustrating embodiments of a userequipment arrangement.

FIG. 8 is a schematic block diagram illustrating embodiments of anetwork controller arrangement.

DETAILED DESCRIPTION

Basically the present solution relates to a method and arrangement thatallows synchronized operation for HS-DSCH serving cell change (HSCC) byletting the user equipment decide an activation time, i.e. a connectionframe number, in which it will move from a serving cell to a targetcell. The user equipment reports this connection frame number to thenetwork controller in a measurement report that triggers the cellchange. The user equipment is then allowed to move to the target cell atthe connection frame number if it gets scheduled on HS-SCCH in thetarget cell before the connection frame number. If it does not, it staysin the source cell.

FIG. 3 shows a wireless communication network 300, using technologiessuch as e.g. UTRAN. The wireless communication network 300 comprisesbase stations serving cells, such as a base station 305 serving a cell306 and a base station 307 serving a cell 308. The base stations 305 and307 are radio base stations, e.g. in a radio access network, and may bereferred to as NodeB. The base station 305 is arranged to wirelesslycommunicate with a user equipment 310 via e.g. radio frequencytransmitters and receivers which also may be responsible fortransmitting and receiving data over an air interface 312. The userequipment 310 may be referred to as a node device. The wirelesscommunication network 300 further comprises a radio network controller315 adapted to control the base stations 305, 307 and other basestations connected to it. The radio network controller 315 is the pointof contact for the user equipment 310 towards the communication network300. The network controller 315 is connected to a core network 316providing services to the user equipment 310.

The user equipment 310 moves from cell 306 towards the neighbor cell308. The user equipment 310 uses cell change procedures to move from onecell to another cell when a stronger neighbor cell is detected. The userequipment 310 moves from one cell to another cell at an activation time.

In the cell change procedure, the user equipment 310 uses a list ofactive set of cells. The list of active set of cells comprises a list ofcells to which the user equipment 310 can move from the serving cell306.

FIG. 4 is a combined flowchart and signalling diagram illustrating anexample of a cell change procedure modified to be synchronized accordingto embodiments of the present solution. According to this example, thetarget cell 308 is preloaded with the high speed configuration during anactive set update procedure (not shown). The method comprises thefollowing steps:

Step 400

A handover evaluation is performed in the user equipment 310 because ithas noticed that another cell in the list of active set of cells hasbecome the strongest one.

Step 401

The user equipment 310 calculates the activation time based on a timingoffset that is previously signalled by the network controller 315. Thetiming offset may be signalled to the user equipment 310 either byactive set update, broadcast or dedicated signalling at call setup.

The calculation of the activation time may be initiated when sendingmeasurement report 1 d during signalling procedure for HS-DSCH servingcell change is triggered in the user equipment 310.

The activation time may e.g. be expressed as a connection frame number(CFN) in which the user equipment 310 will move from the serving cell306 to the target cell 308. The calculated activation time, e.g.comprised in the measurement report 1 d of a handover request message,is transmitted to the network controller 315 forming a basis for ahandover decision.

Step 403

When the network controller 315 receives the measurement report 1 d, itmakes the handover decision whether to move the user equipment 310 tothe target cell 308 or not. If the measurement report 1 d indicates theexistence of a “stronger” neighbour cell 308 than the current servingcell 306, i.e. source cell, and based on other considerations, thenetwork controller 315 may take a decision to move the user equipment310 to this neighbour cell, target cell 308.

Step 404

The network controller 315 sends a radio link reconfiguration preparemessage to the target base station 307, to reconfigure the target basestation 307 informing it also of the connection frame number in whichthe cell change will occur. The user equipment 310 listens to the targetcell High-Speed Downlink Shared Channel (HS-DSCH) Shared Control Channel(HS-SCCH) until the calculated activation time is reached.

Step 405

The target base station 307 sends a radio link reconfiguration readymessage to the network controller 315 when it has performed itsreconfiguration preparations.

Step 406

Then the network controller 315 sends a radio link reconfigurationprepare message to the serving base station 305 to reconfigure theserving base station 305 informing it also of the connection framenumber in which the cell change will occur.

Step 407

The serving base station 305 sends a radio link reconfiguration readymessage to the network controller 315 when it has performed itsreconfiguration preparations.

Step 408

The network controller 315 sends a radio link configuration commitmessage to the target base station 307.

Step 409

The network controller 315 also sends a radio link configuration commitmessage to the serving base station 305.

Step 410

When the target base station 307 has received the radio linkconfiguration commit message it will schedule the user equipment 310 onthe HS-SCCH if the message has been received before the calculatedactivation time. The user equipment 310 regards the cell change approvedupon receipt of an indication of this scheduling.

Step 411

The network controller 315 may also transmit the handover confirmmessage over the target cell 307. This may be done by the networkcontroller 315 transmitting a physical channel reconfiguration messageto the user equipment 310.

Step 412

The user equipment 310 moves to the target cell 307 at the connectionframe number. Note that this is only possible when the networkcontroller 315 schedules the user equipment 310 on HS-SCCH in the targetcell 308 or transmits the handover command in the serving cell 305before the connection frame number. However, if the scheduling messagein step 410 has been received after the activation time, the userequipment 310 remains in the serving cell 305, i.e. no cell change isperformed.

Step 413

There may also be a need for the user equipment 310 to acknowledge thereceipt of the HS-SCCH command. This may be done by the user equipment310 transmitting a “Reconfiguration Complete” message to the networkcontroller 315.

The method described above will now be described seen from theperspective of the user equipment 310. FIG. 5 is a flowchart describingthe present method in the user equipment 310, for setting up anactivation time of a cell change of the user equipment 310 from theserving cell 305 to the target cell 308 in a wireless communicationsnetwork 300. The method comprises the following steps to be performed inthe user equipment 310:

Step 501

The user equipment 310 receives a timing offset from a networkcontroller 315.

In some embodiments the timing offset may be received from the networkcontroller 315 through an active set update procedure.

According to some embodiments the timing offset may be received from thenetwork controller 315 through broadcast or dedicated signalling at callsetup.

In some embodiments the target cell 307 may be preloaded with a highspeed serving cell change procedure.

Step 502

The user equipment 310 calculates a cell change activation time based onthe timing offset.

In some embodiments the activation time may be a connection frame numberin which the user equipment 310 will move to the target cell 308.

Step 503

The user equipment 310 transmits the calculated activation time to thenetwork controller 315.

In some embodiments the activation time may be transmitted to thenetwork controller 315 in a measurement report.

Step 504

The user equipment 310 receives an approval of the cell change from thenetwork controller 315.

In some embodiments the approval of the cell change may comprisescheduling the user equipment 310 on a high speed downlink controlchannel in the target cell 308.

In some embodiments the user equipment 310 may be arranged to monitor atarget cell 308 high speed downlink control channel until the activationtime expires.

Step 505

The user equipment 310 moves from the serving cell 305 to the targetcell 308 at the activation time if the approval has been received.

Step 506

This is an optional step. The user equipment 310 may send anacknowledgement to the network controller 315.

The method described above will now be described seen from theperspective of the network controller 315. FIG. 6 is a flowchartdescribing the present method in the network controller 315 for settingup an activation time of a cell change of the user equipment 310 fromthe serving cell 306 to the target cell 308 in a wireless communicationsnetwork 300. The method comprises the following steps to be performed inthe network controller 315:

Step 601

The network controller 315 transmits a timing offset to the userequipment 310.

In some embodiments the timing offset may be transmitted to the userequipment 310 through an active set update procedure.

In some embodiments the timing offset may be transmitted to the userequipment 310 through broadcast or dedicated signalling at call setup.

In some embodiments the target cell 308 may be preloaded with a modifiedhigh speed serving cell change procedure.

Step 602

The network controller 315 receives an activation time from the userequipment 310.

In some embodiments the activation time may be received from the userequipment 310 in a measurement report.

In some embodiments the activation time may be a connection frame numberin which the user equipment 310 will move to the target cell 308.

Step 603

The network controller 315 decides to move the user equipment 310 to thetarget cell 308.

Step 604

The network controller 315 configures the serving cell 306 and thetarget cell 308 with the activation time.

Step 605

The network controller 315 receives a configuration confirmation fromthe serving cell 306 and the target cell 308.

Step 606

The network controller 315 sends an approval of the cell change to theuser equipment 310.

In some embodiments the approval of the cell change may comprisescheduling the user equipment 310 on a high speed downlink controlchannel in the target cell 308.

Step 607

This is an optional step. The network controller 315 may receive anacknowledgement from the user equipment 310.

To perform the method steps shown in FIG. 5 for setting up an activationtime of a cell change from a serving cell 306 to a target cell 308, theuser equipment 310 comprises a user equipment arrangement 700 as shownin FIG. 7. The user equipment 310 is arranged to be capable of settingup an activation time of a cell change from a serving cell 306 to atarget cell 308. The activation time may be a connection frame number inwhich the user equipment 310 will move to the target cell 308.

The user equipment arrangement 700 comprises a receiver 710 arranged toreceive a timing offset from a network controller 315 through aninterface 312. The receiver 710 may be further arranged to receive thetiming offset the network controller 315 through an active set updateprocedure, and it may also be arranged to receive the timing offset fromthe network controller 315 through broadcast or dedicated signalling atcall setup.

The arrangement 700 further comprises a processor 720 arranged tocalculate a cell change activation time based on the timing offset, anda transmitter 730 arranged to transmit the activation time through theinterface 312 to the network controller 315. The transmitter 730 may bearranged to transmit the activation time to the network controller 315in a measurement report.

The receiver 710 is further arranged to receive an approval of the cellchange through the interface 312, and the processor 720 is furtherarranged to move from the serving cell 306 to the target cell 308 at theactivation time if the approval has been received. The approval of thecell change may comprise scheduling the user equipment 310 on a highspeed downlink control channel in the target cell 308, and the userequipment 310 may be arranged to monitor a target cell 308 high speeddownlink control channel until the activation time expires.

The transmitter 730 may further be arranged to send an acknowledgementthrough the interface 312 to the network controller 315. The target cell307 may be preloaded with a high speed serving cell change procedure.

To perform the method steps shown in FIG. 6 for setting up an activationtime of a cell change from a serving cell 306 to a target cell 308, thenetwork controller 315 comprises a network controller arrangement 800 asshown in FIG. 8. The network controller 315 is arranged to set up anactivation time of a cell change of a user equipment 310 from a servingcell 306 to a target cell 308 in a wireless communications network 300.

The network controller arrangement 800 comprises a transmitter 810arranged to transmit a timing offset to the user equipment 310. Thetransmitter 810 may further be arranged to transmit the timing offset tothe user equipment 310 through an active set update procedure, and thetransmitter 810 may further be arranged to transmit the timing offset tothe user equipment 310 through broadcast or dedicated signalling at callsetup. The arrangement 800 further comprises a receiver 820 arranged toreceive an activation time from the user equipment 310. The activationtime may be a connection frame number in which the user equipment 310will move to the target cell 308.

The network controller arrangement 800 further comprises a processor 830arranged to decide to move the user equipment 310 to the target cell 308and arranged to configure the serving cell 306 and the target cell 308with the activation time. The receiver 810 is further arranged toreceive a configuration confirmation from the serving cell 306 and thetarget cell 308. The transmitter 810 may be further arranged to send anapproval of the cell change to the user equipment 310. The approval ofthe cell change may comprise scheduling the user equipment 310 on a highspeed downlink control channel in the target cell 308. The receiver 820may be further arranged to receive an acknowledgement from the userequipment 310. The target cell 308 may be preloaded with a modified highspeed serving cell change procedure.

The present mechanism for setting up an activation time of a cell changefrom a serving cell 306 to a target cell 308 in a wireless communicationnetwork 300 may be implemented through one or more processors, such as aprocessor 720 in the user equipment arrangement 700 depicted in FIG. 7or a processor 830 in the network controller arrangement 800 depicted inFIG. 8, together with computer program code for performing the functionsof the present solution. The program code mentioned above may also beprovided as a computer program product, for instance in the form of adata carrier carrying computer program code for performing the presentsolution when being loaded into the user equipment 310 and/or networkcontroller 315. One such carrier may be in the form of a CD ROM disc. Itis however feasible with other data carriers such as a memory stick. Thecomputer program code can furthermore be provided as pure program codeon a server and downloaded to the user equipment 310 and/or networkcontroller 315 remotely.

An advantage with embodiments of the present solution is that the HSCCprocedure may be synchronized, also when the cell change command issignalled over HS-SCCH from the target base station 307. This simplifiesL1 termination and user plane handling over lub.

While various embodiments/variations of the present solution have beendescribed above, it should be understood that they have been presentedby way of example only, and not limitation. Thus, the breadth and scopeof the present solution should not be limited by any of theabove-described exemplary embodiments. Further, unless stated, none ofthe above embodiments are mutually exclusive. Thus, the present solutionmay comprise any combinations and/or integrations of the features of thevarious embodiments.

Additionally, while the processes described above are shown as asequence of steps, this was done solely for the sake of illustration.Accordingly, it is contemplated that some steps may be added, some stepsmay be omitted and the order of the steps may be rearranged.

The invention claimed is:
 1. A method in a user equipment for setting upan activation time of a high speed downlink shared channel cell changeof the user equipment from a serving cell to a target cell in a wirelesscommunications network, the method comprising: receiving a timing offsetfrom a network controller through an active set update procedure;calculating a high speed downlink shared channel cell change activationtime based on the received timing offset, the activation time indicatingwhen the user equipment can move to the target cell; transmitting thecalculated activation time from the user equipment to the networkcontroller; receiving an approval of the downlink shared channel highspeed cell change from the network controller; and moving from theserving cell to the target cell at the activation time if the approvalhas been received.
 2. The method of claim 1, further comprising sendingan acknowledgement to the network controller.
 3. The method of claim 1,wherein the activation time comprises a connection frame number in whichthe user equipment will move to the target cell.
 4. The method of claim1, wherein receiving the approval of the cell change comprises receivingan indication that the user equipment has been scheduled on a high speeddownlink control channel in the target cell.
 5. The method of claim 1,wherein the user equipment is operable to monitor a target cell highspeed downlink control channel until the activation time expires.
 6. Themethod of claim 1, further comprising transmitting the activation timeto the network controller in a measurement report.
 7. The method ofclaim 1, wherein the target cell is preloaded with a high speed servingcell change procedure.
 8. A method in a network controller for settingup an activation time of a high speed downlink shared channel cellchange of a user equipment from a serving cell to a target cell in awireless communications network, the method comprising: transmitting atiming offset to the user equipment through an active set updateprocedure; receiving an activation time from the user equipment, theactivation time indicating when the user equipment can move to thetarget cell; deciding to move the user equipment to the target cell;configuring the serving cell and the target cell with the activationtime; receiving a configuration confirmation from the serving cell andthe target cell, and sending an approval of the high speed downlinkshared channel cell change to the user equipment.
 9. The method of claim8, further comprising receiving an acknowledgement from the userequipment.
 10. The method of claim 8, wherein the activation time is aconnection frame number in which the user equipment will move to thetarget cell.
 11. The method of claim 8, wherein sending the approval ofthe high speed downlink shared channel cell change comprises: schedulingthe user equipment on a high speed downlink control channel in thetarget cell; and transmitting to the user equipment an indication thatthe user equipment has been scheduled.
 12. The method of claim 8,further comprising receiving the activation time from the user equipmentin a measurement report.
 13. The method of claim 8, wherein the targetcell is preloaded with a modified high speed serving cell changeprocedure.
 14. A user equipment apparatus in a wireless communicationnetwork wherein the apparatus is operable to set up an activation timeof a high speed downlink shared channel cell change from a serving cellto a target cell, the apparatus comprising: a receiver operable toreceive through an active set update procedure, a timing offset from anetwork controller through an interface; a processor operable tocalculate a high speed downlink shared channel cell change activationtime based on the received timing offset, the activation time indicatingwhen the user equipment can move to the target cell; a transmitteroperable to transmit the calculated activation time through theinterface to the network controller; the receiver is further operable toreceive an approval of the high speed downlink shared channel cellchange through the interface; and the processor is further operable tomove from the serving cell to the target cell at the activation time ifthe approval has been received.
 15. The apparatus of claim 14, whereinthe transmitter is further operable to send an acknowledgement throughthe interface to the network controller.
 16. The apparatus of claim 14,wherein the activation time is a connection frame number in which theapparatus will move to the target cell.
 17. The apparatus of claim 14,wherein the receiver is operable to receive the approval of the highspeed downlink shared channel cell change by receiving an indicationthat the user equipment has been scheduled on a high speed downlinkcontrol channel in the target cell.
 18. The apparatus of claim 14,wherein the apparatus is operable to monitor a target cell high speeddownlink control channel until the activation time expires.
 19. Theapparatus of claim 14, wherein the apparatus is operable to transmit theactivation time to the network controller in a measurement report. 20.The apparatus of claim 14, wherein the target cell is preloaded with ahigh speed serving cell change procedure.
 21. A network controllerapparatus, wherein the apparatus is operable to set up an activationtime of a high speed downlink shared channel cell change of a userequipment from a serving cell to a target cell in a wirelesscommunications network, the network controller comprising: a transmitteroperable to transmit a timing offset to the user equipment through anactive set update procedure; a receiver operable to receive anactivation time from the user equipment, the activation time indicatingwhen the user equipment can move to the target cell; a processoroperable to decide to move the user equipment to the target cell andoperable to configure the serving cell and the target cell with theactivation time; the receiver is further operable to receive aconfiguration confirmation from the serving cell and the target cell;and the transmitter is further operable to send an approval of the highspeed downlink shared channel cell change to the user equipment.
 22. Theapparatus of claim 21, wherein the receiver is further operable toreceive an acknowledgement from the user equipment.
 23. The apparatus ofclaim 21, wherein the activation time is a connection frame number inwhich the user equipment will move to the target cell.
 24. The apparatusof claim 21, wherein the transmitter is operable to send the approval ofthe high speed downlink shared channel cell change by: scheduling theuser equipment on a high speed downlink control channel in the targetcell; and transmitting to the user equipment an indication that the userequipment has been scheduled.
 25. The apparatus of claim 21, wherein thereceiver is operable to receive the activation time from the userequipment in a measurement report.
 26. The apparatus of claim 21,wherein the target cell is preloaded with a modified high speed servingcell change procedure.